Gas turbine engine internal fuel manifolds are typically located inside the engine case adjacent the engine combustor, and thus reside in an extremely hot environment. As is typical with other hardware mounted inside a gas turbine engine, complex connections are required to allow for thermal expansion and to accommodate mismatches in thermal expansion which may exist between components made of different materials and/or which are exposed to different environmental temperatures. Complex systems are more difficult to make and assemble, and tend to add weight and cost. Furthermore, an internal fuel manifold is typically configured as a manifold ring having a fuel inlet tube attached thereto. The attachment between the fuel inlet and the manifold ring may be made in any number of ways including welding, brazing and the like. However, the high temperature and high vibration to which the fuel manifold is exposed within the gas turbine engine, can cause weakening and/or cracking at the joint formed between the fuel manifold ring and its fuel inlet. Therefore, fuel drainage passages may be conventionally introduced using P3 bleed air to dump leaked fuel into a bypass duct in the case of manifold joint failure. That P3 bleed air is constantly wasted, increases fuel inlet temperature and promotes fuel coking.
Accordingly, there is a need to provide improvements to internal fuel manifolds.